There's a new developer question of the week up, and I didn't see any topics on it yet, so I thought I'd provide the link: http://elderscrollsonline.com/en/news/post/2013/11/07/developer-question-of-the-week-46

As for the question, it's a number of things that would make me attached to my character. Their appearance, name, background, and the simple fact that they are my representation into the world of ESO and I'll be experiencing the game through them, like my personal Na'vi. When people address me, they'll most likely use my character's name, and their image is how they'll view me.

What gets me attached to my character is how well my character messes with the storyline the game puts forth, the story is key for me to feel attached to any character in any game I play.

The achievements I have gotten with my character, the dangers he has overcome and in the end also just the familiarity of his face.